The overall aims of this project are to provide more meaningful estimates of human and ecological exposure to contaminants and to evaluate evolving strategies for subsurface restoration in heterogeneous multiphase subsurface systems. These overall aims will be achieved by meeting the following specific aims: 1. to investigate the effect of subsurface heterogeneities on the formation of NAPL dissolution fingers; 2. to evaluate factors that control the formation and morphology of NAPL pools in heterogeneous subsurface systems; 3. to analyze the effect of nonequilibrium sorption/desorption processes in heterogeneous systems on subsurface restoration; 4. to evaluate NAPL-aqueous phase mass transfer, including the role of dissolution fingering, in heterogeneous porous media systems in the presence of solubilizing agents: and 5. to determine the effect of solubilizing agents on subsurface restoration of heterogeneous media contaminated with NAPL pools.